RS4 BRAKE JUDDER

[AudiSingh]

I am new to this Forum as I have only just purchased my 07 RS4 Avant last week, knowing it had serious brake issues.
Not judder, just no brakes, and with pitted discs with high lips on the front.
It was a very low mileage example, but had been standing around too long without regular usage, the brakes were crap despite recent full Audi Service!
Through this forum, I got onto Marcus at Disc Skimmers, who probably is the only guy in the UK that can sort out brake judder and brake issues on the semi floaters of an RS4.
He arrived in his mobile unit and first checked that the discs were within thickness limits, carefully dissembled the calipers and tied them out of the way, finding that the pads were down to the rivets and corroded onto the retaining pins, so not moving as the should.
He then set about skimming and truing each disc on the car with a Pro Cut Lathe, that he had modified himself to deal with RS4 semi-floaters, until they each ran with zero "run out".
He then fitted new EBC, Yellow Stuff pads, supplied by me, taking care that they would freely move on the pins and sliders, using "copperslip" sparingly.
This involved removing some of the yellow pad paint before he was happy.
He took his time and was very thorough and the whole process took 5 hours.
For this excellent and very professional service, he charged me £320.00 (NO VAT)
In talking to him it turned out that he was a motorsport engineer with Formula 1 experience, now working on his own.
He had come across many brake judder issues with RS4's but seemed to have all the answers, particularly with bedding in pads discs and and brake usage.
The other main cause for judder was refurbished wheels that had been painted on the mounting surface, which should be dead flat and true.
Paint and in particular powder coating on the mounting surface of the wheels can affect the wheel and the disc running true and cause judder in a very short time!
The result of his work is that I now have RS4 brakes that work better that the Brembos on my 996 GT3, smooth, but powerful and progressive as brakes should be.
If your brake judder persists I would suggest you contact Marcus, who may be able to solve your problem at very little cost!
His mobile number is 07824 903006 and his website can be found at http://www.discskimmers.com.
I would recommend this guy to anyone with RS brake issues!
I hope that helps - By the way I love the RS4, particularly now I can stop it!
Sprint Blue

Phoned this guy today to get some information for my local place, he was extremely helpful even when he knew I was to give him no business.

Hi peeps

I've had my RS4 B7 for 2 months and the brake judder problem appeared about 4 weeks ago. The previous owner, CopterPilot from this forum, had Audi Harrogate change the discs and pads at the front under warranty after realising they had got warped/defective after 3-4 months of fitting them. So when I had a repeat of the problem, I took the car back to Audi Harrogate, let them keep it for 3 days to perform full diagnosis on the car. When I picked it up, they claimed to have reduced the judder by cleaning corrosion from the front calipers but recommend I change my rears because they had a bit of corrosion which was causing a little bit of judder. This was the advice from Germany Technical team!! I didn't believe the technician and warned them that if not fixed then I would screw!

Typically, I drove 3 miles down the road and the judder was still there, nothing fixed at all!! I did screw at Audi Harrogate but they wouldn't budge until I replaced the rears for £900 to which I told them where to stick it!

Its only until I came across this post, I called Marcus at Discskimmers and he was extremely confident on the phone that he could fix the problem. Only problem was that I had to drive from Leeds to his home in Cambridgeshire! Anyways, I drove down last Saturday morning, he spent 4 hours on all 4 brakes and totally fixed the problem. He even found that my offside rear pad was seized within the caliper and the brake wasn't even working....I was driving like a lunatic with 3 brakes! So much for Audi checking the brakes for safety! So I'm gonna fit some new pads at the rear, probably Ferodo DS2500. Fronts are brand new thanks to CopterPilot and his complaints at Audi!

So lesson here is find a specialist after checking the forums....and never trust Audi or any other dealership cos they will skin you alive just because you have an RS!

As for Marcus, I cant recommend this guy enough, he was professional with everything he did to the brakes, never cut a corner and diligently checked the brakes with a DTI gauge to ensure the discs were true....BTW the Audi technician told me that you can't check floaters with a DTI gauge and that you need a special rolling road to check these brakes!! Fed me so much BS that I was wading through it!

Hope this helps you guys fix brake judder problems!

[Gavla]

After finding this post and having tried a few of the tricks here to alleviate brake judder. i.e. heavy braking due to brake residue, clean up alloy faces after refurb etc... which didn't work I decided before I bought a new set of discs I would give Marcus @ Disc skimmers a call to see if he could work his magic as he's done previously for people.

So I booked it in and had the work done yesterday - he said my discs were quite bad and the judder must have been terrible (which it was). The front discs were skimmed down to 32.2mm so still within manufacturers tolerance of 32mm. (He won't skim below this) All I can say it that it's transformed my car and I echo the previous comments above - what top bloke who is real professional and really knows his stuff.

So if you have brake judder and don't fancy shelling out on new disks then do yourself a favour and call this guy first to see what can be done - it will save you some money.

It cost me £265 (no vat) which included, skim, handle fettle wheels, drill out cross holes, fit new pads. (some of which you might not need)

Happy Days

[guffy]

Looks good.

Wonder if he would pop up to Aberdeen

So are you going to bed them as per the Audi 50 gazillion emergency stops?

[Gavla]

Haha - not sure on that front? I had to pay his petrol money (£70) as it was done at my house which IMO is far less hassle. If he had to do a few up your way then it might be worth his while? Give him a call.

He recommended to go out and do 3 hard stops from 60-20 then drive a few miles and do it again. Whilst they're bedding in they tend to snatch a bit but that will fade after some more heavy braking. Really pleased now and feels much better.

[MikeFish]

Gav, did you measure the thickness before the skim i.e. how much of the disc was removed? 32.2mm means the discs will need replacing soon (aren't they 34 new?). If you're discs were getting on a bit anyway then that's fine but if they were fairly new then that is cutting quite a lot of life off.

[Gavla]

Mike, These were original discs with about 27K miles on them - think they had a hard life before I got hold of them Yes 34mm is new but 32mm is still okay to run and is in tolerance - I believe they make them with plenty of contingency. He did mention that some disks that he's seen in the past went down to 28mm?! but he won't skim below 32mm.

I'm not sure on the exact amount he took off but it was the minimum he needed so I imagine few points of a mm (so not that much) and he said should be fine for at least another 12K miles.

[MikeFish]

Ok thanks Gav. I had a look at mine on the way home and was surprised how quickly they have started to look old. I'm pretty sure you can see the pad deposits on the discs as there appear to be dark patches on them.

[Gavla]

If you have no juddering then I'd imagine all is fine and possibly it's just the brake pad residue as previously mentioned - If you do get any prolonged juddering like me then it's worth pursuing this avenue - also it saves a few quid

[MikeFish]

Yeah mine judders. Started not long after I fitted new discs and pads so mine are fairly new (actually they are probably a year old already!).

[Gavla]

I would imagine that it's one of the wheel components not sitting right that causes all this juddering, maybe spacers or the alloy wheel has got some crap embedded on the face. Mine did and needed fettling as the surface was not smooth and on closer inspection you could actually feel tiny changes in surface through the file as it was catching on bit's of metal that had been squashed into the alloy when it had been torqued up. Also if your wheels have been refurbed then you need to really clean the faces up unless it's been masked.

If yours has been juddering not long from new and it's been a year already then I'd imagine the discs will need looking at sooner rather than later ;-(

I'd take a measurement to see how much you got to play with. I'd imagine though you'll have plenty

[guy]

Looks good.

Wonder if he would pop up to Aberdeen

So are you going to bed them as per the Audi 50 gazillion emergency stops?

I'd be in if he was to pop up to Aberdeen!

[MikeFish]

Gav, do you know where this guy is based / where he travels too?

PS it happened around the time I had my OEM wheels refurbed!

[Gavla]

Mike, He's based in Cambridge and he's a mobile unit so will travel to you - you will have to pay his petrol (round trip) and I think it was 33p per mile.

http://www.discskimmers.com/

marcus@discskimmers.com

P.S. It does sounds like the refurb might be the culprit. I'd be interested to hear how you get on, good luck

[TonyHayers]

Mine were skimmed down to near the limit, the guy reckoned there was plenty still to go. Audi are bound to be over cautious with their wear limits.

I don't believe that anyone has *actually* had warped discs. The fact that Audi dealer replaced discs and pads shows the complete lack of knowledge they have about their own vehicles and is the reason I wouldn't let a main dealer touch my car with a barge pole (or a spanner).

[Timster]

My fronts have juddered for an age.
I now know the pattern to when and if they'll do it. Always seemed to clear when the brakes were hot.
Figured it was either the usual pad residue, blocked holes... blah blah.
My OS did have a very slight (very) warp, which didn't help.

However, I now have a new theory as to what's been causing this.
I know that some owners have had NO trouble when using the "non-sensor pads".

I fitted a new set of Pagids (with sensors), a couple of weeks ago. Apart from some light squealing whilst they bed-in, they've been really good so far.

What I did notice is that the old pads had a very clean groove cut into the plastic/rubber where the old sensor joins the pad.
(ie it's the disk lip itself that triggered the low-pad-warning, not the metal contacts in the pad face).
This was the same on both sides.

So my theory is that A: the spinning disk/lip is always slotting into the groove on the pad-wire (which cant be good) and B: each subsequent pad change is going to have a shorter lifespan as the lip gets bigger and the pads need changing with more material still left on them.

I still have the old pads, so I'll take a photo later, to illustrate.